Metallocene type catalysts are widely used to produce polyolefin polymers such as polyethylene polymers. They have provided efficient processes and a variety of new and improved polymers. While there are many advantages to using metallocene catalysts in olefin polymerizations, there remain significant challenges. For example, metallocene catalysts, in particular supported metallocene catalysts, often have poor flowability, and the supported catalyst particles tend to adhere to surfaces or form agglomerates. Adding other reagents to the supported catalyst composition, such as commonly known antifouling agents or continuity additives/aids may compound the flowability issue. This causes practical problems in storing, transporting, and then delivering the dry supported catalyst composition into a polymerization reactor.
Supported catalyst compositions may also have poor polymerization reactor operability, often caused by uneven distribution of catalyst active sites within the porous particles of the support. In particular, ‘hot-spots’ on the external surface of the support may result from such poor distribution, negatively affecting reactor operability.
It would be desirable to provide a supported catalyst composition for olefin polymerization that has good flowability and that may provide enhanced reactor operability.